This invention relates to hydroxy-terminated aliphatic polyethers having pendant alkyl azide groups, and their use in propellants and explosives.
Solid double-base propellants such as those used for rocket fuel are fabricated by combining an explosive (or "energetic") liquid binder with a fuel (commonly nitrocellulose). One class of such binders are azido compounds, which are particularly advantageous because of their relatively cool burning temperature, which leads to less corrosion and a longer life for the materials used to contain the explosives. Examples of such compounds are alkyl diazidopolyepoxides having one or two azide groups and four or more carbon atoms per monomer unit, as disclosed in Frankel, et al., U.S. Pat. No. 4,268,450 (May 19, 1981); and the poly(gembisazidomethyloxetanes) of Earl, et al., U.S. Pat. No. 4,405,762 (Sep. 20, 1983). Other disclosures of these and similar compounds appear in Azami, et al., U.S. Pat. No. 3,694,383 (Sep. 26, 1972) and Frankel, et al., U.S. Pat. No. 4,303,414 (Dec. 1, 1981).
Unfortunately, those azido polyethers which are known generally require starting materials which are either expensive or difficult to synthesize, and some are solid, rendering them inconvenient to use in the manufacture of explosives.